Generation of extreme-ultraviolet beams with time-varying orbital angular momentum

Author
Abstract
Light fields carrying orbital angular momentum (OAM) provide powerful capabilities for applications in optical communications, microscopy, quantum optics, and microparticle manipulation. We introduce a property of light beams, manifested as a temporal OAM variation along a pulse: the self-torque of light. Although self-torque is found in diverse physical systems (i.e., electrodynamics and general relativity), it was not realized that light could possess such a property. We demonstrate that extreme-ultraviolet self-torqued beams arise in high-harmonic generation driven by time-delayed pulses with different OAM. We monitor the self-torque of extreme-ultraviolet beams through their azimuthal frequency chirp. This class of dynamic-OAM beams provides the ability for controlling magnetic, topological, and quantum excitations and for manipulating molecules and nanostructures on their natural time and length scales.
Year of Publication
2019
Journal
Science
Volume
364
Start Page
eaaw9486
Date Published
2019-06
ISSN Number
0036-8075
URL
https://science.sciencemag.org/content/364/6447/eaaw9486.full
DOI
10.1126/science.aaw9486
JILA PI
Journal Article